1. Field of the Invention
This invention relates to a connector with a double lock mechanism which has, in addition to a flexible lock arm in each terminal receiving hole of a housing, a terminal locking plate inserted into intermediate portions of the terminal receiving holes.
2. Background
FIGS. 6(A) and 6(B) show one example of a conventional connector with a double lock mechanism. Upper and lower rows of terminal receiving holes b are provided in a connector housing a, and a primary flexible lock arm d for preventing rearward withdrawal of a terminal c is provided in each receiving hole b. The size of the flexible lock arm d is limited because, for example, of the multi-pole compact design of the connector, and therefore the lock arm d does not provide a sufficient terminal retaining force. Accordingly, the terminal c is secondarily locked by a terminal lock plate thereby reinforcing the locking of the terminal.
More specifically, windows f1 and f2 are formed respectively through an upper wall al of the connector housing and a partition wall a2 in the connector housing (FIG. 6(A)), and the terminal lock plate e is inserted into the housing through the windows, so that a retaining portion el of the lock plate e is engaged with a shoulder c1 of the terminal c (FIG. 6(B)) to thereby achieve secondary locking together with the primary locking of flexible lock arm d.
The problem associated with the double lock construction shown in FIGS. 6A and 6B, is that it necessary to form the window f2 in part of the partition wall a2 in order to allow the insertion of the terminal lock plate e. Therefore, as shown in FIG. 7(A) on an enlarged scale, there is not a sufficient space for supporting the fulcrum portion d1 of the flexible lock arm d in each of the upper terminal receiving holes b. Accordingly, as shown in FIG. 7(B), the flexible lock arm d is liable to be damaged at its proximal portion d1, for example, by a tension exerted on a connected wire, so that the intended primary retaining force can not be obtained.
With the above problem in view, it is an object to this invention to provide a connector with a double lock mechanism which provides a high locking force to retain terminals without the possibility of damaging any flexible lock arm for effecting primary locking of the terminal.